1. Field of the Invention
The present invention relates to a dose-rate measuring system which is installed in nuclear reactor facilities, nuclear fuel reprocessing facilities or the like, and uses an ionization chamber as a radiation detector.
2. Description of the Related Art
A conventional dose-rate measuring system includes an ionization chamber that detects a radiation incident from the outside and outputs ionization current; a current-signal cable that transmits the ionization current outputted from the ionization chamber; a high-voltage cable that supplies a high voltage so as to operate the ionization chamber; and a signal converter that converts the ionization current, which is inputted via the a current-signal cable, into a signal so as to output, and outputs the relayed high voltage to the high-voltage cable. In the dose-rate measuring system, connectors of a current-signal MI (mineral insulation) cable and a high-voltage MI cable are respectively connected to connectors of a current-signal cable and a high-voltage cable, and connecting portions of the connectors are waterproofed by bonding tapes. Moreover, in the dose-rate measuring system, a cabinet of the ionization chamber, a cable shield, a housing of the connectors, and a cabinet of the signal converter, which are respectively insulated, are connected in series, and a single-point ground is performed at a measuring unit, which receives a convert signal outputted from the signal converter and supplies a high voltage, and moreover, the insulated ionization chamber is fixed to a chassis (refer to Patent Document 1).